Mesa (r300-bufmgr): r300: Fix crash in r300ClearBuffer

[Nicolai Hähnle]

Module: Mesa
Branch: r300-bufmgr
Commit: 1ca0e2ac03b4fd95ee9cd2dbe82bb7a0e9c1614d
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=1ca0e2ac03b4fd95ee9cd2dbe82bb7a0e9c1614d

Author: Nicolai Haehnle <nhaehnle at gmail.com>
Date:   Mon Sep 29 09:40:50 2008 +0200

r300: Fix crash in r300ClearBuffer

That function can currently be called without a radeon_renderbuffer
when only Z/stencil needs clearing.

---

 src/mesa/drivers/dri/r300/r300_ioctl.c |   13 +++++++++----
 1 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/mesa/drivers/dri/r300/r300_ioctl.c b/src/mesa/drivers/dri/r300/r300_ioctl.c
index 36a2736..c3d0d72 100644
--- a/src/mesa/drivers/dri/r300/r300_ioctl.c
+++ b/src/mesa/drivers/dri/r300/r300_ioctl.c
@@ -93,11 +93,16 @@ static void r300ClearBuffer(r300ContextPtr r300, int flags,
 	cp_wait(r300, R300_WAIT_3D | R300_WAIT_3D_CLEAN);
 	end_3d(rmesa);
 
-	BEGIN_BATCH(19);
-	OUT_BATCH_REGSEQ(R300_RB3D_COLOROFFSET0, 1);
-	OUT_BATCH_RELOC(0, rrb->bo, 0, DRM_RELOC_TXOFFSET);
-	OUT_BATCH_REGVAL(R300_RB3D_COLORPITCH0, cbpitch);
+	if (flags & CLEARBUFFER_COLOR) {
+		assert(rrb != 0);
+		BEGIN_BATCH(4);
+		OUT_BATCH_REGSEQ(R300_RB3D_COLOROFFSET0, 1);
+		OUT_BATCH_RELOC(0, rrb->bo, 0, DRM_RELOC_TXOFFSET);
+		OUT_BATCH_REGVAL(R300_RB3D_COLORPITCH0, cbpitch);
+		END_BATCH();
+	}
 
+	BEGIN_BATCH(15);
 	OUT_BATCH_REGSEQ(RB3D_COLOR_CHANNEL_MASK, 1);
 	if (flags & CLEARBUFFER_COLOR) {
 		OUT_BATCH((ctx->Color.ColorMask[BCOMP] ? RB3D_COLOR_CHANNEL_MASK_BLUE_MASK0 : 0) |